module Phisol
  Compiler.class_eval do

    def on_function  statement
      #puts statement.inspect
      return_type , name , parameters, kids , receiver = *statement
      name =  name.to_a.first
      args = parameters.to_a.collect do |p|
        raise "error, argument must be a identifier, not #{p}" unless p.type == :parameter
        Parfait::Variable.new( *p)
      end

      if receiver
        # compiler will always return slot. with known value or not
        r = receiver.first
        if( r.is_a? Parfait::Class )
          class_name = r.value.name
        else
          if( r != :self)
            raise "unimplemented case in function #{r}"
          else
            r = Virtual::Self.new()
            class_name = method.for_class.name
          end
        end
      else
        r = @clazz
        class_name = @clazz.name
      end
      raise "Already in method #{@method}" if @method
      @method = @clazz.get_instance_method( name )
      if(@method)
        puts "Warning, redefining method #{name}" unless name == :main
        #TODO check args / type compatibility
        @method.source.init @method
      else
        @method = Virtual::MethodSource.create_method(class_name, return_type, name , args )
        @method.for_class.add_instance_method @method
      end
      @method.source.receiver = r
      puts "compile method #{@method.name}"


      #frame = frame.new_frame
      kids.to_a.each do |ex|
        return_type = process(ex)
        raise return_type.inspect if return_type.is_a? Virtual::Instruction
      end
      @method.source.return_type = return_type
      @method = nil
      Virtual::Return.new(return_type)
    end
  end
end